Effect of environment upon mechanical behavior of structural ceramics for application in the DOE Ceramic Technology for Advanced Heat Engines Project

Technical Report · Fri Jun 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6727123· OSTI ID:6727123

Hecht, N L; Graves, G A; McCullum, D E; Berens, A P; Goodrich, S; Wolf, J D; Hoenigman, J R; Yaney, P; Grant, D; Hilton, S; Jang, S D ^[1]

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1. Dayton Univ., OH (USA). Research Inst.

The primary goal of this research was to determine the effect of environment upon toughening and strength in commercially available transformation-toughened ceramics (partially stabilized ZrO{sub 2} (PSZ) and dispersion toughened Al{sub 2}O{sub 3} (DTA)). Emphasis was on understanding the mechanism(s) responsible for environmentally induced strength degradation in the temperature range of 25 to 1050{degree}C. Dynamic fatigue techniques (four-point flexural strength as a function of stressing rate) were used in a three-phase plan to investigate fracture strength and slow crack growth in environments containing controlled amounts of water vapor. Similar measurements were also conducted in inert atmospheres (dry N{sub 2}) to distinguish intrinsic effects from environmentally derived effects. In addition, the effects of aging (extended exposure at elevated temperatures and selected atmosphere conditions) on the candidate materials at low temperatures were studied. The activities pursued and the results obtained are described in this report. 40 refs., 53 figs., 22 tabs.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dayton Univ., OH (USA). Research Inst.
• Sponsoring Organization: DOE/CE
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6727123
• Report Number(s): ORNL/Sub-84-00221/1; ON: DE90014770
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
ALUMINIUM OXIDES
MECHANICAL PROPERTIES
CERAMICS
AGING
ZIRCONIUM OXIDES
CRACK PROPAGATION
FATIGUE
FLEXURAL STRENGTH
HEAT ENGINES
PROGRESS REPORT
WATER VAPOR
X-RAY DIFFRACTION
ALUMINIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DOCUMENT TYPES
ENGINES
FLUIDS
GASES
OXIDES
OXYGEN COMPOUNDS
SCATTERING
TRANSITION ELEMENT COMPOUNDS
VAPORS
ZIRCONIUM COMPOUNDS
330102* - Internal Combustion Engines- Diesel
360203 - Ceramics
Cermets
& Refractories- Mechanical Properties